Open Firmware is now free

Posted Nov 17, 2006 21:54 UTC (Fri) by giraffedata (subscriber, #1954) [Link]

Seems redundant to use two separate BIOSes

A good reason to have two separate programs is the same thing that led to having two separate programs (BIOS and OS) on the first ISA computers: BIOS is married to the hardware and OS is married to the application. You mix and match in order to have any combination of application and hardware.

When OF runs without a separate BIOS, it contains a machine-type-dependent BIOS. The only difference really is one of packaging and naming. To me, it makes the most sense to package bona fide BIOS with the hardware and package everything else separately, for more flexibility and better compatibility.

In the case of Sparc, Mac, and IBM System P, the OF instance is designed for a particular machine type and supplied with that machine, so there's no reason to have a machine type compatibility layer (BIOS) under it. But if you're going to separately distribute one OF to run on a variety of machines distributed by someone else, separate BIOS makes a lot of sense.

Posted Nov 18, 2006 17:40 UTC (Sat) by hollis (subscriber, #6768) [Link]

Of course, inside Open Firmware you have different components: the Forth interpreter and the low-level firmware (responsible for initializing the memory controller, discovering PCI devices, etc) are obviously separate. As a systems vendor you would naturally use the same Forth interpreter and combine it with a different low-level firmware for each system.

By the way, "BIOS" is just the name for the standard PC firmware interface. The generic term is "firmware". :)